The risk of exposure to nerve agents is an increasing concern for military personnel as well as civilians. In response to this threat, various countermeasures have been developed that are capable of neutralizing chemical weapons including nerve agents. Some compounds have also been developed that can report the presence of the nerve agent. For example colored compounds may change colors, or may have a change in their electromagnetic spectrum absorbance or fluorescence that can be measured using an analytical instrument such as a spectrometer.
Henry et al. [US 2009/0187060 A1] discloses 2,3-butanedione monoxime (also known as diacetyl monoxime), and alkali salts thereof such as potassium 2,3-butanedione monoximate (KBDO) that are suitable for neutralizing toxic chemicals including organophosphates.
Formula 1, Potassium 2,3-butanedione monoximate:

The following scheme (Scheme 1) shows the reaction of KBDO with the organophosphorus chemical agent VX.

Hydroxy oximes have been used as organophosphorus nerve agent sensors [Dale and Rebek Jr., Angew. Chem. Int. Ed. 2009, 48, 7850-7852]. In these compounds aromatic cores are inserted between an oxime and a hydroxy group. When the oxime reacts with an organophosphorus compound there is a shift in the absorbance and/or fluorescence of the compound. This shift in light absorbance or emission properties is measured using a spectrometer and can be used to detect the presence of the organophosphorus compounds.
Formula 2, an example of a hydroxy oxime of Dale et al.:

Scheme 2 shows the reaction of the ortho-hydroxy oxime of Dale et al. with an organophosphorus compound.

Another family of compounds has been used for detecting nerve agents, as disclosed by Corcoran et al. [U.S. Pat. No. 7,674,627 B2]. The sensing compounds have an alpha effect nucleophile group that undergoes specific nucleophilic substitution and rearrangement reactions with phosphorous-based nerve agents. This family of compounds has a reporter group covalently linked to an alpha effect nucleophile group. When these compounds react with phosphorous-based nerve agents, they chemically rearrange and release a new optically active compound (for example Malachite green). The color can be detected by a spectrometer or in some cases by the human eye (visual inspection).
Formula 3, example of a sensor compounds of Corcoran et al.:

The sensor compounds of Corcoran may be produced from a triarylmethane dye, such as Malachite green, by reaction with NaCN followed by MeMgBr and H2NOH with catalysts as shown in Scheme 3.

Scheme 4 shows an example of a sensor compound of Corcoran et al. reacting with an organophosphorus compound.

A commercially available skin decontaminant product is Reactive Skin Decontamination Lotion, or RSDL®, which is sold by Emergent BioSolutions (Rockville, Md.). This product, RSDL®, was originally developed by the Canadian Department of National Defence (DND) and has since been adopted by several military services around the world. The RSDL® product contains 2,3-butanedione monoxime (DAM) as one of the active ingredients. The active ingredients are dissolved in a solvent composed of polyethylene glycol monomethyl ether and water. DAM is known to react with and neutralize organophosphorus nerve agents. 2,3-butanedione monoxime and its potassium salt are desirable decontaminants because they are proven in existing and approved commercial products.
The above prior art relating to compounds capable of decontaminating and/or reporting the presence of an organophosphorus chemical agent suffer from at least one of the following limitations: they only decontaminate or neutralize the organophosphorus chemical agent (no color change); they exhibit a change in color that is subtle and requires a spectrophotometer to detect or to quantify the change; or the compound does not combine the preferred 2,3-butanedione monoxime or 2,3-butanedione monoximate with a dye compound to provide both the preferred neutralizing agent and a color-indicating feature.